Dinâmica da vegetação através do índice de vegetação e sua relação com variáveis meteorológicas no município de Ingá-PB

Abstract

The changes in land use and land cover, their causes and consequences, it has been analyzed through some methods, in order to seek measures that allow, for example, improvement in air and soil quality, as well as the increase in the biodiversity of the fauna and flora. Due to the importance of vegetation, especially in air and soil quality, it is necessary to monitor its behavior. From this perspective, the objective of this work was to analyze the vegetation dynamics in the city of Ingá-PB through the Normalized Difference Vegetation Index (NDVI) and its relation with the meteorological variables (rainfall, land surface temperature and evapotranspiration). Were used the vegetation data of the product MOD13Q1, the data of land surface temperature of product MOD11A2, the evapotranspiration data of the product MOD16A2 of the MODIS / TERRA sensor, totaling 268 images, and monthly historical data of precipitation obtained by the Executive Agency of Management of Waters of the State of Paraiba (EAMW), in the period from 2012 to 2016. The use of precipitation data allowed the identification of the rainiest months (June and July), the months of drought (November and December) and the months of low precipitation (January, February, March and April). It is during the dry season that plants tend to lose their leaves as a way to survive the period of water shortage, avoiding dehydration through transpiration. However, in the rainy season these plants present a biological regeneration, returning to develop their photosynthetic activities. It is also during this period that vegetation accumulates the nutrients necessary for survival during the dry season. It was observed, through the results, that there was a decrease in vegetation index values, and an increase in temperature, for periods with low rainfall, while in periods of high rainfall there was an increase in NDVI and it cooling in the surface temperature. Among the observed variables, the one that best explains NDVI behavior, in general, is evapotranspiration, with the exception of December, due to the product specifications MOD16. Thus, there is a considerable explanation of vegetation dynamics through these climatic variables, although it is necessary to analyze other variables that may interfere in their behavior. The NDVI corresponds well to the analysis of vegetation dynamics regarding the monitoring of its space-temporal alteration and facilitates the understanding generating satisfactory results for the studies about the vegetative dynamics in response to climatic conditions and environmental variables. By means of remote sensing techniques it is possible to contribute to the formation of a database that meets the needs of improving environmental planning in regions with few easily accessible environmental data.